It is interesting that the laws of physics do not change just because you are trying to make high quality gigacastings. Structural gigacastings must be free of miss runs just the same as structural pistons. I am not surprised that the cross hatch invented to solve miss run piston defects is now appearing as a feature of gigacastings.

My casting mentors conjectured that the cross hatch anchored the flow fronts and created a path for venting at the bottom of the grooves. All I can add to that is that the method actually solved piston miss run issues. Otherwise there is no structural need to have cross hatch on pistons. Gigacastings fit into the same category. There is no structural need for cross hatch but miss runs which cause cracks and weak spots are definitely a problem